An electric machine may include a stator and a rotor arranged to be rotatable with respect to the stator. The stator may include a stator core having a plurality of slots and a stator coil that is wound on the stator core. The rotor may be configured to be rotated by an electromagnetic force with the stator or by an external driving force.
A part of the stator coil may be conductors formed as copper wires in order to increase a space factor with respect to the slots. The stator coil may be formed by connecting a plurality of conductors inserted into the plurality of slots to each other in a specific pattern.
A conventional stator for a rotary electric machine may have the following problems. In some cases, based on a connection pattern of the conductors of the stator core, connection parts of the conductors are spaced apart from each other by a relatively long distance in a circumferential direction of the stator core. Accordingly, a connection ring formed to connect the conductors with each other is used. This may cause the number of components to be increased, and the fabrication costs to be increased.
In some cases, based on a connection pattern of the conductors of the stator core, the connection parts of the conductors are arranged in a middle layer of a corresponding slot. This may cause a difficulty in connecting the conductors (jump lines) with each other.
In some cases, based on a connection pattern of the conductors of the stator core, the conductors are protruded toward outside of the stator in a radial direction of the stator, in order to avoid interference between the conductors. Accordingly, a case for accommodating the stator therein may be provided with an accommodation portion protruded in a radial direction of the stator core. This may cause a difficulty in fabricating and installing the case.